Objective. To examine the determinants of the utilization of health care services among the population of older adults in Mexico. Three types of health care services are analyzed: preventive care, visits to the doctor, and hospitalizations. Material and Methods. Data was used from the 2001 Mexican Health and Aging Study (MHAS/ENASEM) and estimates were made using multivariate probit regression methods. Results. Socioeconomic factors, health conditions reported by the individuals, and the availability of health insurance are signi.cant determinants of the differential use of services by older adults. Conclusion. Specific health conditions are important determinants of use of the various types of health care services. For all three types, however, the availability of health insurance is an enabling factor of health care use. Older age is associated with greater propensity to use health care services but its effect is small when controlling for health conditions.